Time switch



June 21, 1938.

Filed Oct. 15; 1935 5 Sheets-Sheet 1 WITNESSES INVENTOR June 21', 1938. CONRAD 2,121,585

TIME SWITCH Filed Oct. 15, 1955 3 Sheets-Sheet 3 M4 TIIIIIIIIIIIIIIIIA IIII/I/I/IIII/lllfl INVENTOR TEY Patented June 21, 1938 UNITED STATES PATENT OFFICE TIME SWITCH Pennsylvania Application October 15, 1935, Serial No. 45,043

7 Claims.

My invention relates to astronomical time switches and more particularly to switches of this character which control electric circuits and which automatically adjust themselves for dinerent on and off periods in accordance with the variations in the length of daylight at different seasons of the year.

One object of my invention is to provide an astronomical time switch which may be easily and inexpensively manufactured, installed and maintained in operation.

Another object is to provide an astronomical time switch for turning on and off electric lamps or other devices in the evening and in the morning which may be easily and quickly set or adjusted to turn the lamps on at any desired time after sunset and to turn them off at any desired time before sunrise.

Another object is to provide an astronomical time switch which may be easily set or adjusted to turn on a circuit at any desired time after sunset and to turn it off at any predetermined time regardless of the time of sunrise.

Heretofore it has been necessary to design as- 5 tronomical switches for the particular latitude of the country in which they are to be used. For

instance, a switch designed for use in a section of the country falling in say latitude 40 will not operate accurately in a section of the country falling in latitude 80. This presented difficulties in the manufacture and sale of such switches in that if they were to be carried in stock for customers, it was necessary to manufacture and stock a large number of different designs, thus increasing the expense and also the opportunity for errors in carrying difierently designed devices for supplying the demand from different sections of the country. Therefore, it is also an object of my invention to provide a switch for universal use and one which may be easily and quickly adjusted for use in any section of the country.

The invention itself, however, together with its additional objects and advantages, may be best understood. from the following description taken in conjunction with the accompanying drawings, in which,

Figure l. is a view, in front elevation. of an astronomical switch embodying my invention,

Fig. 2 is a view, in front elevation, of the instrument shown in Fig. 1 with the face plate and its supporting plate'removed, (see lines IIII of Fig. 5)

Fig. 3 is a top plan view of the time switch shown in Fig. 1;

Fig. 4 is a view in side elevation (as seen from the right) of the time switch shown in Fig. 1;

Fig. 5 is a view taken on the line V-V of Fig.1;

Fig. 6 is a view representing a vertical cross section through the means for setting the time switch to operate Hours after sunset, taken along the line VIVI of Fig. 2;

Fig. '7 is a top plan View of the switch operated by the timing mechanism shown in Figs. 1 to 5;

Fig. 8 is a top plan view of the levers for jointly controlling the operation of the time adjusting devices in accordance with the times of sunset and sunrise; and

Fig. 9 is a bottom plan View of the astronomical cam and its adjusting scale for controlling the time adjusting devices shown in Fig. 8.

Referring more particularly to the drawings, the time switch is provided with a frame comprising a base plate I upon which suitable corner posts 2, 3, 4 and 5 are mounted for supporting a central plate 6 and a top plate i. The plates are held in a spaced apart parallel relation by the corner posts to provide supports in which the clock mechanism and time switch associated therewith may be mounted. The ends of the corner posts extend through the base plate and the top plate and a plurality of screw threaded nuts 8 are mounted thereon to hold the parts together. A face plate It is mounted upon the top plate and is spaced a short distance therefrom and parallel thereto by a plurality of spac ing studs I I. The face plate l is provided with a dial H for the months of the year and a clock dial 13 for the hours and minutes of the day.

A calendar hand I4 is mounted upon a shaft IS in position to be moved over the dial I?! by a clock mechanism 16 for indicating the month and the approximate day of the year when the switch is in operation. The divisions of the months are indicated on the dial by their first letters and the division for each month is separated into three sections so that the pointer will give an indication of the approximate day of the month as well as the month involved. A suitable knob 23 is disposed on the upper end of the shaft l for adjusting the calendar hand M to agree with the month and time of the month in which the instrument is operated.

An hour hand i! and a minute hand l8 are disposed for operation over the dial I3 for indicating the time of day. The minute hand I8 is mounted upon and rotated by a shaft 20 and the hour hand is frictionally mounted upon a hollow shaft 2| rotatably disposed on the shaft 20. A suitable knob 22 is disposed on the outer end of the shaft 20 for adjusting the minute hand and the hour hand to indicate the time of day accurately. The lower part of the dial I3 is marked with cross hatch lines to indicate approximately night time.

The calendar hand I 4 rotates once a year, the hour hand rotates once each day and the minute hand rotates once every hour, therefore, when the device is in operation it will indicate to the observer the month, approximately the day of the month, and the time during the day.

Although any suitable motor may be used for driving the clock mechanism, I have illustrated a clock motor 24 for this purpose as comprising a toothed wheel 25 disposed on a shaft 33 having its ends supported in biasing blocks 34 and 35, a timing shaft 26 for driving the wheel 25, a pair of pole members 21 mounted on the timing shaft, and an electromagnet 28 for cooperation with the pole pieces in oscillating the timing shaft; A hair spring 26a is attached to the timing shaft for regulating its rate of operation. A contact making spring 29 is mounted on the post 2 and insulated therefrom for the purpose of making and breaking the circuit for the electromagnet 28 in accordance with the oscillations of the timing shaft 26. If desired, current may be supplied to the motor through a suitable copper oxide rectifier 30. Inasmuch as this motor does not constitute a part of the present invention, no further description of it is here given, but if more details are desired, they may be obtained from my copending application Serial No. 625,147, filed July 27, 1932 for improvement in Alternating-current direct-current clock.

A worm gear 31 is disposed on the shaft 33 in position to mesh with and rotate a worm wheel 33 and its shaft 39. A pinion 40 disposed on the shaft 39 drives the clock mechanism by rotating a gear wheel 42 on the shaft 20. Inasmuch as the minute hand I8 is mounted upon the shaft 20, it is driven around the dial l3 in accordance with the operation of the motor 24 and the chain of speed reducing gears 31, 38, 4D and 42. The gear wheel 42 is mounted upon the shaft 20 by means of a friction clutch 44, which permits adjustment of the shaft 20 and therefore the hour hand I! and the minute hand l8 by operation of the knob 22 when it is desired to reset the clock.

The hour hand I! is driven by the power of the shaft 20, through the medium of a chain of speed reducing gears comprising a pinion 46 on the shaft 2|! meshing with a gear wheel 41 on a shaft 48 which operates a pinion 48 on its upper end above the plate 6 and rotates a gear wheel 58 which constitutes an integral portion of, and therefore, rotates the hollow shaft 2| upon which the hour hand is mounted. The hour hand is mounted on its shaft 2| by a friction collar (see Figs. 3 and so that it may be adjusted relative to the minute hand. By reason of these speed-reducing pinions and gear wheels, it will be seen that the rotation of the shaft 20 by the motor 24 will effect a corresponding slower rotation of the shaft 2|, so that the hour hand I! thereon will travel once around the dial I3 each day while the minute hand I8 is making twenty four revolutions each day and, therefore, that as long as the clock motor 24 is operating accurately and the minute and hour hands are properly adjusted the dial 3 will indicate the time.

The calendar hand I4 is also driven by the shaft 20 through a chain of speed reducing gears which cause it to be rotated once each year for indieating the time of the year in months and fractions thereof. This chain of speed-reducing gears (Figs. 3 and i) comprises (in addition to the pinion 46 on shaft 20 and gear wheel 41 on shaft 48) a pinion 53 mounted on and driven by the shaft 48 in position to engage and rotate a gear wheel 54 mounted on a shaft 55, a pinion 56 disposed on the shaft 55 in position to engage and rotate a gear wheel 5'! disposed on a shaft 58, pinion 59 disposed on the shaft 58 in position to engage and rotate a gear wheel 59 disposed on a shaft 5|, and a pinion disposed on shaft 6! in position to engage and rotate a gear wheel 63 mounted on the shaft i5. The gear wheel 63 is secured to the shaft l5 by friction clutch 54 to permit adjustment of the calendar hand l4 independently of the gear wheel 63 by means of a knob 23 to any desired position.

The chain of speed reducing gear wheels 53, 54, 56, etc. just described is so designed that accurate operation of the clock motor 24 will cause the calendar hand Hi to complete one rotation each year and thereby causes it to indicate on the calendar dial l2 the month and fraetion thereof of the calendar year. It will also be noted by the gear chains described, that operation of the motor 24 will drive the hour hand, the minute hand, and the calendar hand in such manner that any one may readily determine the month, the approximate day of the year and the hour and minute of the day by observing the dials.

The time switch provided for operation by the clock mechanism is indicated by the numeral and comprises a circuit malaing cam member ll,

a cooperating brush l2, and a circuit-breaking cam '13 on a base member 34, (Figs. 5 and 7). The cam 13 and its base member 14 are rotatably mounted upon the shaft 2|. A gear wheel is mounted upon the upper end of the base memher 14 and firmly affixed thereto by a circular nut l6 so that the cam '13 may be rotated on the shaft 2| by rotating the gear wheel 15.

The circuit-making cam "H is provided with hub Tl firmly affixed to an insulating bushing 18 which is rotatably mounted upon the body member 14 of the cam 13 so that the cams H and 13 may be rotated relative to each other. A shoulder 19 is disposed on the lower portion of the insulating bushing 78 to prevent electrical connection at that point between the two cams. A gear wheel 82 is screwed upon the top portion of the bushing 18 and an insulating washer 8| is disposed between the wheel 82 and the cam hub T! to prevent electrical connection therebetween. The gear wheel 82, the washer ill, the bushing 78, the hub TI and the cam II are firmly locked together, so that the cam may be moved relative to the cam l3 by rotation of the gear wheel 82. Hence, it is seen that cams "H and 13 being rotatable on the shaft 2| and rotatable relative to each other, may be adjusted by relative movement of the gear wheels 15 and 82 or either cam may be moved independently of the other cam by operation of its own gear wheel.

The brush I2 is pivotally mounted upon the outer end. of an arm 84, which constitutes a portion of and extends from the hollow shaft 2 i. A spring member 35 biases the free end of the brush '12 toward the rims of the cams l'l ant. 33. Inasmuch as the arm constitutes a of and rotates with the hollow shaft 2| which makes one revolution each day in accordance with the hour hand of the clock, the brush i2 is dragged around the rims of the cams II and I3 once each twentyfour hours.

The brush I2 is electrically connected to the arm 84 by a conductor 86 and the arm is grounded to the machine by a brush 81 riveted to the plate 6 in position to slidably engage the underside of the gear wheel 50 when it and the arm 84 rotate with the hollow shaft 2|. The contact making cam II is provided with a channel 90 in which is disposed one end of a spring brush 3 I, the other end of which is mounted in an insulated block 92 secured to the corner post 3 by a pair of screws 93. The brush BI is electrically connected by a conductor 94 to a binding post 95 and the frame is provided with a binding post 96 so that switch I may be connected in any circuit which it is desired to control by the time switch.

As shown in Fig. I the contact making cam II is provided with a shoulder section 96 upon which the brush I2 rides when the time switch is closed, a shoulder 91 and a cutaway portion 98. The cam I3 is provided with a shoulder section I00, a shoulder IOI and a cutaway portion I02. With the cams in the position shown, the brush I2 is held out of engagement with the circuit making cam II by the shoulder section I00 of the cam 73. However, when the arm 84 is moved clockwise, the brush I2 slides ofi the shoulder IOI of cam I3 and into contact with the rim 96 of the cam II. Hence, the switch is closed during its further operation until the brush I2 reaches the point where it falls off the shoulder 91 of the cam II and into engagement with the rim portion I02 of the cam I3 which holds the brush 12 out of engagement with the rim of the circuitmaking cam II. Hence it will be seen that relative rotation of the cams II and I3 by their operating gear wheels I5 and 82 will lengthen or shorten the time the brush I2 is in contact with the contact making surface 96 of the cam II during the daily rotation of the brush by the arm 84. It will also be evident that, when the brush I2 is traveling along the contact making portion 96 of the cam II, a circuit is completed from the binding post 95 through the conductor 94, brush 9!, hub member I'I, conducting cam II, brush I2, conductor 86, arm 84, brush 81, and the frame of the machine to the binding post 96.

Therefore, it is seen that while the brush I2 is travelling around the cam members II and I3 once each day, the switch is closed during that portion of the time that the brush I2 is in contact with the contact-section 96 of cam II. During the remainder of the travel of the brush I2, the circuit is open because the brush then rides upon the outer rim of the cam 83 and out of contact with cam II. Hence the length of time the circuit remains closed may be adjusted by so rotating one or both of the cams as to vary the difference between the position of the shoulder I! of cam I3 and the shoulder 91 of cam II.

It is also seen that it is the position of the cam 73 which determines when the circuit is turned on and that it is the position of the cam II which determines when the circuit is turned off.

The means for adjusting the cam I3 to the time desired for turning on the circuit comprises a gear wheel I08 disposed on a hub I01 (Figs. 2, 3 and 6) rotatably mounted upon a shaft I08 having its lower end mounted in the plate 6 and its upper end mounted in the plate I, and an internal gear wheel IIO mounted on the underside of the gear wheel I06 and spaced therefrom by suitable spacing blocks I09. The inter a pinion I I I rotatably mounted by a pin I I2 upon an astronomical on lever H3 one end of which is provided with a hub II 4 which is rotatably mounted upon the lower portion of the shaft I00 with its lower end in engagement with the plate IE6. The other end of the lever I I3 is controlled in movement by an astronomical cam to be described later. The pinion III not only engages the internal gear wheel I08 but it also engages a gear wheel IIB which is firmly mounted upon the shaft I08 by means of a pin III through its hub portion.

As shown, the shaft 108 is provided with a shoulder IZI which is disposed to engage the plate I and to be pulled up against that plate by the action of a clutch washer I28 disposed be= tween the face plate I0 and the plate I. -By reason of the friction washer I28, the shaft I08 will stay in the position to which it may be rotated by operating the knob I26. By reason of this construction, the cam I3 may be adjusted to its proper position by operating the hand knob I26 to rotate the shaft I08, which rotates gear wheel IIG, which, in turn, rotates the pinion II I on its pin II2 thereby eiTecting movement of the inner gear wheel I00. Inasmuch as the gear wheel I08 is attached to the gear wheel I06 by the blocks I09, that gear wheel rotates the gear wheel I5 with which it engages and consequently rotates the cam I3 associated therewith when the knob I26 is turned.

The rotation of the cam I3 is designed to adjust the time switch to close at any desired time relative to sunset and as shown in Fig. 1, the knob I has disposed upon it a hand or pointer I29 which indicates on the dial I30 the hours after sunset at which the time switch will close to turn on the lamps when it is adjusted in accordance with the dial.

The means for adjusting the cam II to turn off the lamps at a desired period before sunrise comprises a mechanism the same as that described for turning on the lamps at sunset and hence will not be described in detail. This mechanism is indicated broadly by the dial I3I marked Hours before sunrise, a pointer i32 thereon attached to a knob I33 for operating a shaft I34. This shaft in turn, operates a gear wheel I35 to rotate a pinion I36 mounted on an astronomical off lever I40 to be described later. The pinion I36 engages and rotates an internal gear wheel I3! mounted on an external gear wheel I38, which, in turn, engages and rotates the gear wheel 82 for adjusting the cam II.

Hence the time for turning the lamps off just before sunrise may be set by turning the knob I33 to effect the rotation of the gear wheel 82 and the consequent rotation of the cam II to such a point that its shoulder or broken away portion 91 will permit the brush I2 to fall into engagement, at the correct time, with the circuit opening cam II which keeps the brush from touching the contact cam II and thereby turns the lights oif at the desired time.

Inasmuch as the time of sunset and the time of sunrise vary in accordance with the seasons of the year, I have provided a device for automatically varying the operation of the means for adjusting the time switch cams in accordance with the variations of sunset and sunrise. In order to accomplish this automatic adjustment, the astronomical on lever H3 is connected at its outer end by a pivot screw II8 to a link II9, the other end of which is pivotally connected by nal teeth of the wheel IIO are disposed to engage a screw I20 to an astronomical lever I2I, the

lower ends of which are pivotally disposed on the plate I. An astronomical cam disk I22 is mounted upon the clock shaft I5 for controlling the movement of the lever I2I, link H9 and the arm H3 in one direction.

A biasing spiral clock spring I24 having one end secured to the hub I I4 of the arm I I3 and its other end secured to the corner post 5, biases the arm H3 in the other direction and opposite to the pull of the link H9. The cam I22 is rotated in accordance with the yearly rotation of the clock shaft I5 and thereby moves the astronomical lever I 2| and link H9 against the action of the spring I24 in accordance with the seasons of the year, thus so controlling the position of the pin ion III mounted on the arm H3 that it will also change the on adjusting device in accordance with the seasons of the year.

The astronomical lever I40 upon which the pinion I36 is supported is pivotally mounted by a hub I4Il upon the shaft I34 and is similar to the lever H3, except that its outer end is disposed to engage a roller I4I on the underside of the arm H3, so that movement of the arm H3 by the link I I9 will also effect a corresponding movement of the arm I46. The arm I40 is also biased away from the link H9 by a spiral spring I42, one end of which is attached to the corner post 4 and the other end of which is coiled around and attached to the hub I40 By reason of this construction, the position of the arm and the pinion I36 mounted thereon is adjusted by the movement of the cam disk I22 against lever I2I and the action of the link H9, in accordance with the variations of the times of sunrise and consequently so varies the position of the cam II that it cuts off the lamp circuit at the selected time before sunrise each day, in accordance with the seasons of the year.

Heretofore, in constructing astronomical time switches, it has been necessary to provide for each latitude a switch constructed for that particular latitude, so that the switches would automatically follow correctly the variations in the time of sunrise and the time of sunset. This occasioned considerable difficulty by reason of the necessity of making a special machine for each latitude. I overcome this difiiculty by so con structing and mounting the cam I22 that the device may be easily adjusted for any latitude, and thus permit the same switch to be operated accurately in any latitude.

In practicing my invention, I provide the cam I22 with a slot I43 and an adjusting block I44. The slotis sufficiently wide and long to permit the shaft I5 to pass through it and to also permit the cam to be moved transversely of the shaft. The block is firmly affixed to the shaft I5 directly underneath the cam, in which position it acts as a support and a position-adjusting means for the cam. A cap bolt I45 passes through the slot I43 and into a screw-threaded aperture in the adjusting block I44. The head of the cap bolt I45 rests upon and engages the upper surface of the cam I22, so that the cam will be firmly held to the adjusting block when the cap bolt is screwed tightly into the adjusting block. The underside of the cam H2 is provided with a latitude scale I48 and the block is provided with a point or mark I46 which cooperates with the scale to indicate the latitude for which the device is adjusted.

In Fig. 9, the adjusting block is shown with its marker I46 disposed opposite the gradation 35 correponding to latitude 35. In this position, the

cam 22 will operate accurately for latitude 35. If it is desired to have the device operate for latitude 30, the cap bolt I45 may be loosened and the cam moved on block I44 until the marker I46 corresponds to latitude 30 on the scale. The cap screw is then tightened to hold the cam I 22 in the position to which it is adjusted. In this position, the cam I 22 will cause the machine to operate accurately in latitude 30. Thus it is seen that by loosening the adjusting block I44 and moving the cam thereon until the marker I46 and the latitude marked on the scale I48 agree, and then tightening the cap screw to hold the cam I22 in place, the cam will then cause the machine to operate accurately and automatically for the latitude indicated, thereby doing away with the necessity of providing a different time switch for the various latitudes.

The operation of the timing switch is as follows: The switch and clock are prepared for operation by moving the hour hand II against its frictional engagement with the hollow shaft 2I until it is disposed in proper relation to the minute hand I8. The knob 22 is then rotated to set the hour hand and the minute hand to indicate the correct time on the dial I3. This action can take place without disturbing the motor by reason of the frictional engagement between the shaft 20 and the gear wheel 42 operated by the motor.

Next, the knob 23 is rotated to indicate on the dial I2 the correct month and the division thereof corresponding to the time at which the instrument is being set. The operation of the knob 23 also rotates the astronomical cam I22 to the proper position for the time and year indicated by the pointer I4 on the dial I2. This adjusting rotation is permitted by reason of the frictional engagement between the shaft l5 and the gear wheel 63.

The switch I0 is next adjusted for turning on the lamps (not shown) by rotating the knob I25 to cause the arrow I29 to indicate on the dial I30 the time after sunset at which it is desired to light the lamps. This operation rotates the cam I3 to such a position that it will permit the time switch III to close the timing circuit represented by the conductors 86 and 94. The next step is to turn the knob I33 and thereby rotate the pointer I32 to that point on the dial I3I which corresponds to the time before sunrise at which it is desired to have the lamps turned off. This operation causes the switch cam "H to rotate to the point where the circuit will be cut off by the action of the brush I2 at the correct time.

Inasmuch as the clock is now set for operation, the motor 24 is started by connecting it to any suitable source of energy (not shown) and the clockwork begins to run. As the time set for turning on the lights at a predetermined time after sunset approaches (assuming that the clock has been set during the daytime), the brush I2 is rotated around the rings of the cams II and I3 to a point where it drops off the shoulder IUI on the contact-breaking cam 13 into engagement with the contact-making portion 96 of the cam H. The engagement of the brush I2 with the cam II completes the circuit through the conductors 86 and 94 for turning on the lamps.

As the night passes and the time at which the lamps are to be turned off before sunrise approaches, the brush I2 is moved around the rim of the cam II by the operation of the clock shaft 2I and its arm 84 to a point where the brush falls off the shoulder 91 of the cam II and into engagement with the outer rim I02 of the cam I3, in which position it is held out of engagement with the contact making cam II and thereby breaks the circuit through the conductors 86 and 94, thus turning off the lamps.

As the months pass, the operation of the calendar shaft I5 by the clock mechanism rotates the astronomical cam I22 so that that cam, by pressing against the lever I2I, moves the link H9 and the levers I53 and its in opposition to the pull of the springs I24 and I42, to so adjust the position of the pinions I36 and III as to change the position of the switch cams I! and I3 in accordance with the season of the year. This adjustment will be effected, as shown, by reason of the fact that the gear wheel I I6 is firmly disposed on the shaft I88 which is biased by the friction clutch 28 against free rotation; therefore, when pressure is exerted against the pinion MI by the arm H3, that pinion revolves around the gear H6 and so doing rotates the internal gear it, which moves the gear 566 to effect rotation of the gear'wheel I5, and thereby rotate the cam I3. This changes the time for the time switch to be turned on in accordance with the change in the time the sun sets.

At the same time, the pinion I36 on the arm I is revolved around the gear I35 by the arm and thereby causes rotation of the internal gear wheel I31, which effects rotation of the gear whee'i I38, thereby rotating the cooperating gear wheel 82 which in turn effects rotation of the switch cam II to a point where its shoulder 51 will cause the brush I2 to turn off the lights before sunrise at the time desired in accordance with the season of the year. Hence it is seen that the time switch, after being started, operates automatically with out attention for all seasons of the year.

In some cases, it may be desired to adjust the time switch in such manner that it will turn off the lamps at some stated time during the night, say. at one oclock, and not at a time indicated as so many hours before sunrise. This stated time of one oclcck will not be changed by any variation the time of the sunrise, and the time switch will not vary it in any way. In order to accomplish this novel result, I have provided a pin I on the underside of the arm MI) for cooperation with a latch IEI mounted upon the corner post 4. The scale I3! of the face plate is also provided with an outer scale I52 marked with the hours from 12 to 5 for cooperation with the pointer I32. When it is desired to have the lamps turned off at, say, one oclock, the pointer I32 is rotated by the knob I33 to the index I of the scale I52 and the latch I5I is placed against the pin I50 on the arm Mo to hold the free end of the arm I40 out of engagement with the roller I4I on the underside of the arm H3, regardless of the effect of the biasing spring I42. With the catch disposed against the pin I50, the arm Mil will not be operated by the astronomical cam I22 and its associated levers and will remain stationary against the catch IEI. Therefore, when the off adjusting means is set at, say, one

oclock, the operation of the clock. means will cause the brush I2 to slide off the conducting cam II and into engagement with the opening cam I3, at the hour set on the dial I52, regardless of its relation to the actual time of sunrise, thereby turning the lamps off.

It will be apparent that my astronomical time switch may be advantageously utilized to control some power devices directly. However, when a large amount of power is to be controlled, it will be preferable to utilize the time switch III to I actuate some relay or electro-magnetic circuit controller (not shown) for controlling such large amount of power. Inasmuch as such relays or controllers are not part of this invention and are old and well known in the art, no description thereof will be given.

By reason of the foregoing illustration and description, it will be seen that I have provided an accurate astronomical time switch which may be used in any section of the country regardless of its latitude and which may be easily and quickly adjusted for many desired conditions in connection with the operation of electrical circuits for lamps or other devices.

Although I have shown and described certain specific embodiments of my invention, many modir'lcations thereof and changes therein are possible. Therefore, my invention is not to be restricted except insofar as is necessitated by the prior art and by the scope of the appended claims.

I claim as my invention:

1. In an astronomical time switch, a clock mechanism for indicating the time of the year including a shaft and means for rotating the shaft on its axis only once each year, a switch, means responsive to operation of the clock mechanism for closing the switch and for opening the switch each day, means for setting the switch to be closed at a predetermined time each day relative to the time of sunset on that day, a cam disk provided with a slot, means fixing the cam disk on the shaft with the shaft extending through the slot to cause the cam disk to be rotated once each year by the rotation of the shaft, means for adjusting the position of the cam disk on the shaft in accordance with the latitude in which the time switch is to be used, a lever, means for biasing the lever against the outer periphery of the cam disk and means responsive to operation of the lever by the rotation of the cam disk for controlling the operation of the switch in accordance with the seasons of the year.

2. In an astronomical time switch, a clock mechanism for indicating the time of year, a switch, means responsive to operation of the clock mechanism for closing the switch and for opening the switch each day, means for setting the switch tobe closed at a predetermined time each day relative to the time of sun-set that day, means responsive to the operation of the clock mechanism for changing said setting means in accordance with the season of the year, said changing means including a cam provided with a slot in which an operating member of the clock mechanism is disposed, a block firmly afiixed to said operating member, a cap screw for fastening the cam to the block, and a cooperating scale and mark on the cam and the block for indicating the latitude for which the cam is adjusted on the block.

3. In an astronomical time switch, a clock mechanism for indicating the time of the year, a switch comprising a brush, a circuit making cam and a circuit opening cam, and means for rotatably supporting the cams in cooperative relation to each other, means responsive to operation of the clock mechanism for moving the brush around the outer rims of the said cams daily, means for biasing the brush toward said rims, said circuit breaking cam being provided with a rim portion extended to prevent the brush from engaging the circuit making cam during one part of its travel and said circuit making cam having an extended portion to prevent the brush from engaging the circuit breaking cam during another portion of its travel, and means for rotating said cams relative to each other for setting the times at which the switch shall be opened and closed during the daily rotation of the brush around the rims of the cams by the clock mechanism.

4. In an astronomical time switch, a clock mechanism for indicating the time of the year, a switch comprising a brush, a circuit making cam and a circuit opening cam, and means for rotatably supporting the cams in cooperative relation to each other, means responsive to operation of the clock mechanism for moving the brush around the outer rims of the said cams at a rate of once each twenty-four hours, means for biasing the brush toward said rims, said circuit breaker cam being provided with a rim portion extended to prevent the brush from engaging the circuit making cam during one part of its travel and said circuit making cam having an extended rim portion to prevent the brush from engaging the circuit breaking cam during another portion of its travel, a setting means for rotatably adjusting the position of the circuit making cam and a setting means for rotatably adjusting the position of the circuit breaking cam to cause the switch to close and to open at predetermined times relative to the times of sunset and sunrise, and means responsive to the operation of the clock mechanism for changing said setting means in accordance with the seasons of the year to automatically preserve the predetermined times of closing and opening the switch relative to the times of sunset and sunrise.

5. In an astronomical time switch, a clock mechanism for indicating the time of the year, a switch comprising a brush, a circuit making cam and a circuit opening cam, means for rotatably supporting the cams in cooperative relation to each other, means responsive to operation of the clock mechanism for moving the brush around the outer rims of the said cams at a rate of once each twenty-four hours, and means for biasing the brush toward said rims, said circuit breaking cam being provided with a rim portion extended to prevent the brush from engaging the circuit making cam during one part of its travel and said circuit making cam having an extended rim portion to prevent the brush from engaging the circuit breaking cam during another portion of its travel, a setting means for rotatably adjusting the position of the circuit making cam and a setting means for rotatably adjusting the position of the circuit breaking cam to cause the switch to close and to open at predetermined times relative to the times of sunset and sunrise, and means responsive to the operation of the clock mechanism for changing said setting means in accordance with the seasons of the year to automatically preserve the predetermined times of closing and opening the switch relative to the times of sunset and sunrise and means for adjusting the position of the changing means in accordance with the latitude in which the switch is to be used.

6. In an astronomical time switch, a clock mechanism for indicating the time of the year, a

switch comprising a brush, a circuit making cam and a circuit opening cam, means for rotatably supporting the cams in cooperative relation to each other, means responsive to operation of the clock mechanism for moving the brush around the outer rims of the said cams at a rate of once each twenty-four hours, means for biasing the brush toward said rims, said circuit breaking cam being provided with a rim portion extended to prevent the brush from engaging the circuit making cam during one part of its travel and said circuit making cam having an extended rim,

portion to prevent the brush from engaging the circuit breaking cam during another portion of its travel, a setting means for rotatably adjusting the position of the circuit making cam and a setting means for rotatably adjusting the position of the circuit breaking cam to cause the switch to close and to open at predetermined times relative to the times of sunset and sunrise, means for adjusting the position of the setting means comprising means for biasing the setting means toward the position to which they have been adjusted, and a lever and a single astronomical cam responsive to operation of the clock mechanism for moving the setting means against the operation of the biasing means in accordance with the seasons of the year to automatically preserve the predetermined times of closing and opening the switch with reference to the times of sunset and and a circuit opening cam, means for rotatably supporting the cams in cooperative relation to each other, means responsive to operation of the clock mechanism for moving the brush around the outer rims of the said cams at a rate of once each twenty-four hours, and means for biasing the brush toward said rims, said circuit breaking cam being provided with a rim portion extended to prevent the brush from engaging the circuit making cam during one part of its travel and said circuit making cam having an extended rim portion to prevent the brush from engaging the circuit breaking cam during another portion of its travel, a setting means for rotatably adjusting the position of the circuit making cam and a setting means for rotatably adjusting the position of the circuit breaking cam to cause the switch to close and to open at predetermined times relative to the times of sunset and sunrise, means for adjusting the position of the setting means comprising means for biasing the setting means 5 toward the positions to which they have been adjusted, a lever and a single astronomical cam responsive to operation of the clock mechanism for moving the setting means against the operation of the biasing means in accordance with the sea sons of the year to automatically preserve the predetermined times of closing and opening the switch with reference to the times of sunset and sunrise, and means for changing the position of the astronomical cam whereby it will operate for the latitude in which the switch is to be used.

FRANK CONRAD.

(iii 

